Best Multi Marketplace Platform?

We are looking for the best Multi Marketplace Platform which we can use with Amazon as well as our Website which is hosted by Shopify. We have a large amount of SKUs which will need to be supported by these plateforms. The part we are having trouble with is that we sell on Houzz.com, 11Main.com which a lot of platforms don't support.

It will be a great help if someone knows of a Multi Marketplace Platform that will work for us.Thank you